In recent years, the use of an RFID (Radio Frequency Identification) inlay using a semiconductor chip which is capable of reading and writing information for information management of articles and physical distribution management or she like is progressing.
The RFID inlay is configured by a IC chip having a memory which records information, an antenna which receives a radio wave and transmits information which is recorded in the memory of the IC chip via the radio wave, and a base material on which the IC chip and the antenna are mounted.
Additionally, in recent years, introducing a system that the RFID inlay is incorporated in a vehicle number plate and information of the owner or the vehicle or the like is detected without contact to be helpful for preventing crimes or the like is under consideration (refer to Patent Document 1).
In a vehicle number plate of Patent Document 1, a slot is formed on a metal plate thereof and an RFID inlay is arranged on the back surface of the metal plate so as to straddle the slot. Additionally, an external light layer is formed on a front, surface of the metal plate in order to improve visibility at night,